MyPond capability
Pond bathymetry and water volume
Turn depth readings into contours, surface area, and a real gallon count.
MyPond turns a traced shoreline and a scatter of depth readings into a bathymetric map and a measured water volume. You trace the pond on satellite imagery, enter depths wherever you took them, and MyPond interpolates a depth grid, draws contour lines at a chosen interval, and integrates the grid to a volume in cubic feet, acre-feet and gallons. That volume is what every treatment dose in MyPond is sized against, so it replaces the usual surface acres times guessed average depth estimate.
Inputs, analysis, outputs
What you provide
- A traced shoreline
- You draw the pond outline on satellite imagery. That polygon sets surface area and shoreline length, and it doubles as the zero depth contour: everything outside it is land.
- Depth measurements
- Any set of point depths, from two readings to a full sonar transect. Each one is a latitude, a longitude and a depth in feet. They do not have to be on a grid or evenly spaced.
What MyPond does
- Inverse distance weighting onto a regular grid
- MyPond lays a grid over the pond, roughly 3 foot cells for small ponds and about 5 foot cells for larger ones, and estimates a depth at every cell. Nearer readings count for more, on an inverse square weighting. The shoreline is held at zero depth so the interpolation cannot push water past the bank.
- Marching squares contouring
- The depth grid is traced into isobath lines at a contour interval chosen to suit the pond depth, producing the contour map you see over the imagery.
- Frustum integration for volume
- Volume comes from integrating the grid cell by cell, then is cross-checked by treating each pair of contour areas as the ends of a frustum and summing those slices. Two independent paths to the same number is the check on a bad depth reading.
What you get back
- Surface area
- In acres, from the traced polygon.
- Shoreline length
- In feet, from the same polygon.
- Maximum and mean depth
- In feet, from the interpolated grid.
- Volume
- In cubic feet, acre-feet and gallons. Acre-feet divides cubic feet by 43,560; gallons multiplies cubic feet by 7.48052.
- Contour lines
- Drawn over the satellite imagery, and carried into the aeration layout tools.
- Bathymetric surface area
- The area of the pond bottom following the actual contours, which is larger than the flat surface area and matters for bottom treatments.
How it works
Why interpolation rather than a depth formula
The common shortcut is surface acres times an assumed average depth, often max depth times 0.4. That assumption is doing all the work, and it is wrong in opposite directions for a steep-sided excavated pond and for a shallow flooded pasture. Interpolating from real readings removes the assumption. It also means the answer improves as you add readings rather than staying fixed at the first guess.
How many depth readings you need
Two readings will produce a volume, but the useful floor is enough points to describe the shape: the deep hole, the shelf, and the places where the slope changes. Readings clustered in one arm of the pond will extrapolate poorly into the arm you did not visit, and the contour map makes that obvious at a glance.
Ponds that are not one basin
A pond traced as several disconnected water bodies is handled as several polygons in one grid, and the volume totals every piece rather than only the largest.
Common questions
Can MyPond estimate my pond volume without depth readings?
It needs at least two depth readings to interpolate. With only a traced shoreline you get surface area and shoreline length, which are enough for surface-acre dosed products but not for volume dosed ones.
What units does MyPond report pond volume in?
Cubic feet, acre-feet and gallons, from the same integration.
Does the pond volume update when I add more depth readings?
Yes. Volume is recomputed from the full set of readings, so the number moves as the survey gets denser and then settles.
Related
MyPond is built by Natural Waterscapes. See live data from a real pond, or what it costs.